Patients with galactosemia have difficulties metabolizing galactose (milk sugar) from breastmilk, infant formula and dairy products. Newborn screening prevents death by early diagnosis and treatment but in spite of early treatment many patients suffer from cognitive and neurological impairment which impact on their quality of life and independence and create a severe burden for patients and families.

The exact mechanism of these long term complications is poorly understood as is the large variability of severity of complications between patients. At this time, it is not possible to predict the severity of complications for the individual patient at the time of diagnosis. This may result in parents’ anxiety, late treatment or unnecessary and potentially harmful treatment.

Our hypothesis is that the long term complications result from abnormalities in the structure of protein (enzymes and hormones) and fat (myelin) in the brain and other tissues due to abnormalities in the building in of galactose: “ galactosylation ” , and that the individual ability to metabolize small amounts of galactose (residual oxidation capacity) determines the individual severity of galactosylation abnormalities and thus the individual outcome.

In this project we aim to study brain MRI scans of patients, as galactosylation is highly important for brain development and function. We will study patients’ brain MRI scans and relate the results to the residual oxidation capacities and cognitive abilities of these pa tents. We expect that this project will truly increase knowledge of this disorder and will assist us to be able to predict the severity of complications for individual patients.

This project is part of a larger study, in which all results of sub - projects will be combined aiming to develop and validate new diagnostic methods and ultimately new therapeutic options in Classical Galactosemia.